Reading to children was a source of fulfillment in the life of M.P., a 40-year-old aunt, kindergarten teacher, and reading specialist … But all of that changed when, on a Thursday morning, she found herself standing at the front of her class and holding in her hands an indecipherable mystery.

It was the attendance sheet. The same sheet she had used for years, and to hear M.P. tell it, it might as well have been covered in hieroglyphs.

She had suddenly and inexplicably lost the ability to read.

The school principal was as perplexed as she, and M.P. was promptly discharged from work and into the care of her mother.

Eventually, her mother took M.P. to hospital, where it was discovered that she had suffered a stroke. The stroke had caused a rare syndrome:

Alexia without agraphia, also commonly referred to as “word blindness,” in which patients lose the ability to read, but can still write and comprehend the spoken word…

It was first described in 1892 by Joseph Jules Dejerine, who hypothesized that this unique pattern of deficits is caused by subcortical lesions that functionally isolate the left angular gyrus, or “language zone”, from the visual cortex…

Determined to overcome her disability, M.P. tried to teach herself to read again, but despite her best efforts, she just could not recognize letters by sight. It was only when she hit upon the idea of feeling the shape of the symbols that she made progress:

To see this curious adaptation in practice is to witness the very unique and focal nature of her deficit. Given a word, M.P. will place her finger on the first letter and begin to trace each letter of the alphabet over it in order, until she recognizes that she has traced the letter she is looking at.

“That is the letter M”, she declares, after tracing the previous 12 letters of the alphabet with her finger while deciphering a word in front of her. Three letters later, she is able to shorten this exercise with a guess: “This word is ‘mother,’” she announces proudly.

Cuomo et al comment that “the language zone is robbed of its visual inputs but remains intact”; in essence, the finger-tracing routine is a way of getting information to that area by non-visual means.

Strangely, however, the sight of some words provoke emotions in M.P., although she is not conscious of knowing the word meaning:

Nor are such intuitions uncommon for M.P. when looking at written words, for although she cannot read a word by sight, it may nevertheless elicit emotions that seem surprisingly appropriate. For instance, when shown the word “dessert” in writing, M.P. exclaimed, “Oooh, I like that!”

I find this dissociation between feeling words and understanding them the most remarkable part of this case.

It suggests that either a) M.P.’s ability to decode writing is intact, on some subconscious level, which might require a revision to neuroscience of language textbooks, or b) words can elicit emotions by some kind of a conditioned association, requiring no understanding (or even power of understanding), which would have big implications for “subliminal messaging”.

It would be pretty natural for words to be recognized as objects by the general vision system along with being interpreted as words. And if they’re emotionally strong they should acquire such associations independent of their lexical meaning as well.

John

I was about to say pretty much the same thing. It’s just associative learning and / or conditioning depending on the word. It need not be recognized as a word per se.

Neurocritic

Very interesting case, which fits in with the extensive literature on acquired disorders of reading (not cited in the article). With all the left brain/right brain crap that gets bandied about, real differences between the cerebral hemispheres can become obscured. The left hemisphere is dominant for reading (and language more generally), from the decoding of letter strings (orthography) to the translation of letter strings into sounds (phonology), to extraction of meaning (semantics). One possibility is that we could invoke the dual route model of reading: the sublexical route from orthography to phonology to semantcs, and the lexical (whole word) route to semantics. Perhaps M.P. is using the whole word route.

However, because of the extensive damage to left hemisphere reading areas, she can’t consciously read or even identify single letters using the left hemisphere. The splenium of the corpus callosum (that would normally transfer visual info across hemispheres) is damaged, as are left visual cortical regions. Yet visual information *is* reaching her right hemisphere, which is able to unconsciously identify single words, especially those with certain properties (i.e., concrete or emotional). If you remember the old Gazzaniga split brain studies, words presented in the left visual field (to the right hemisphere) were not consciously identified in some patients, yet they could elicit some sort of reaction. I think that’s what you’re seeing here. The word “dessert” is a concrete word and an enjoyable food, so it prompted a reaction that the left hemisphere “interpreter” couldn’t describe explicitly.

There have been other patients with alexia who’ve adopted a kinesthetic reading strategy, but those papers weren’t cited by the authors, either.

http://blogs.discovermagazine.com/neuroskeptic/ Neuroskeptic

Excellent comment, thanks. As you say, this could be a real case of the “holistic right brain” at work!

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About Neuroskeptic

Neuroskeptic is a British neuroscientist who takes a skeptical look at his own field, and beyond. His blog offers a look at the latest developments in neuroscience, psychiatry and psychology through a critical lens.